Little has been done to directly evaluate the impact of cognitive changes in Mild Cognitive Impairment (MCI) on the performance of everyday tasks. By virtue of their high risk for progression to dementia, individuals with MCI also are at high risk for decline in the abilities needed to function effectively and independently in society. They are likely to experience a loss of functional skills that lies somewhere between the subtle decrements associated with normal aging and the frank deficits associated with a dementia such as Alzheimer's disease. A critical question in the conceptualization of MCI is how changes in memory and other cognitive abilities influence the performance of everyday tasks over a 2 to 4 year period of time--a period that for many individuals will mark the transition from MCI to dementia. A clearer understanding of the relationship between cognitive abilities and real world task performance will not only provide information about potential mechanisms for functional change in MCI but also will target areas for future multi-component intervention studies. The objectives of the proposed research are to examine the relationships between specific cognitive abilities and a spectrum of real world tasks that are strongly tied to autonomous functioning, quality of life, health, and avoidance of adverse outcomes such as hospitalization and mortality, and to evaluate how these relationships change over time among individuals with MCI relative to normal controls. These objectives will be achieved by comparing over time the functional abilities of a well-characterized, clinic-based sample of 75 to 90 individuals with MCI to those of an equally well- characterized, clinic-based sample of 75 to 90 age-matched, cognitively normal individuals. Specific aims are to: (1) compare the performance of individuals diagnosed with MCI to that of age- and education-matched normal controls on a variety of indices of everyday function, with primary emphasis on driving and financial skills; (2) compare longitudinal changes in functional performance in individuals with MCI to longitudinal changes in controls with annual assessments over intervals of 2 to 4 years; (3) examine cognitive predictors of functional performance and functional change over time in individuals with MCI and in normal controls; and (4) explore the hierarchy of functional change in MCI by examining decrements in functional abilities compared to those of normal controls and by comparing the magnitude of loss in each functional domain to losses across the range of functional abilities under evaluation, both at baseline and over time.